In testing forward acceleration, braking deceleration, and lateral cornering acceleration of automobiles and other vehicles, various instruments have been used which employ the familiar mass-spring principle with fluid damping. Such instruments have also been provided with auxiliary peak-holding pointers which are pushed ahead of the main acceleration-indicating pointer and remain at positions corresponding to the maximum or peak excursions along the scale until they are reset by the operator. Commonly two such holding pointers are provided in an instrument with a zero-center scale, to hold or "record" the peak acceleration experienced in either direction.
There are needs for improvement in the following respects: (a) balancing of the holding pointers, (b) adjustability from outside the case, (c) adaptability to mounting in various orientations, and (d) simplicity and economy of manufacture.